Modeling of a negative ion source. II. Plasma-gas coupling in the extraction region
- Max Planck Institute fuer Plasmaphysik, EURATOM Association, Wendelsteinstrasse 1, Greifswald, D-1749 (Germany)
- Istituto di Metodologie Inorganiche e di Plasmi IMIP-CNR, Sect. Bari, via Orabona 4, Bari, I-70126 (Italy)
The production, destruction, and transport of H{sup -} in the extraction region of a negative ion source are investigated with a 1D(z)-3V particle-in-cell electrostatic code. The motion of charged particles (e, H{sup +}, H{sub 2}{sup +}, and H{sup -}) in their self-consistent electric field is coupled with the neutral particles [H(n=1) and H{sub 2}(X{sup 1}{sigma}{sub g}{sup +}, v=0,...,14)] dynamics and vibrational kinetics of H{sub 2}. Neutral influxes into the domain are determined by the simulation of the expansion region. Surface and volumetric processes involving plasma and neutrals have been included by using different Monte Carlo collision methods. Calculations show the influence of the plasma grid bias and of the magnetic filter on the plasma parameter profiles. In particular, a transition from classical to complete reverse sheath is observed using a positively biased plasma grid. The influence of the magnetic filter is small. The importance of the hot-atom mechanism on the surface negative ion production is shown.
- OSTI ID:
- 21254564
- Journal Information:
- Physics of Plasmas, Vol. 15, Issue 10; Other Information: DOI: 10.1063/1.2985854; (c) 2008 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 1070-664X
- Country of Publication:
- United States
- Language:
- English
Similar Records
Origin of extracted negative ions by 3D PIC-MCC modeling. Surface vs Volume comparison
Study of volume and surface effects in pure hydrogen discharges